/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.apis.content;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import android.content.ContentProvider;
import android.content.ContentValues;
import android.content.ContentProvider.PipeDataWriter;
import android.content.res.AssetFileDescriptor;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.os.ParcelFileDescriptor;
import android.util.Log;

/**
 * A very simple content provider that can serve arbitrary asset files from our
 * .apk.
 */
public class FileProvider extends ContentProvider implements
		PipeDataWriter<InputStream> {
	@Override
	public boolean onCreate() {
		return true;
	}

	@Override
	public Cursor query(Uri uri, String[] projection, String selection,
			String[] selectionArgs, String sortOrder) {
		// Don't support queries.
		return null;
	}

	@Override
	public Uri insert(Uri uri, ContentValues values) {
		// Don't support inserts.
		return null;
	}

	@Override
	public int delete(Uri uri, String selection, String[] selectionArgs) {
		// Don't support deletes.
		return 0;
	}

	@Override
	public int update(Uri uri, ContentValues values, String selection,
			String[] selectionArgs) {
		// Don't support updates.
		return 0;
	}

	@Override
	public String getType(Uri uri) {
		// For this sample, assume all files are .apks.
		return "application/vnd.android.package-archive";
	}

	@Override
	public AssetFileDescriptor openAssetFile(Uri uri, String mode)
			throws FileNotFoundException {
		// Try to open an asset with the given name.
		try {
			InputStream is = getContext().getAssets().open(uri.getPath());
			// Start a new thread that pipes the stream data back to the caller.
			return new AssetFileDescriptor(openPipeHelper(uri, null, null, is,
					this), 0, AssetFileDescriptor.UNKNOWN_LENGTH);
		} catch (IOException e) {
			FileNotFoundException fnf = new FileNotFoundException(
					"Unable to open " + uri);
			throw fnf;
		}
	}

	@Override
	public void writeDataToPipe(ParcelFileDescriptor output, Uri uri,
			String mimeType, Bundle opts, InputStream args) {
		// Transfer data from the asset to the pipe the client is reading.
		byte[] buffer = new byte[8192];
		int n;
		FileOutputStream fout = new FileOutputStream(output.getFileDescriptor());
		try {
			while ((n = args.read(buffer)) >= 0) {
				fout.write(buffer, 0, n);
			}
		} catch (IOException e) {
			Log.i("InstallApk", "Failed transferring", e);
		} finally {
			try {
				args.close();
			} catch (IOException e) {
			}
			try {
				fout.close();
			} catch (IOException e) {
			}
		}
	}
}
